Vital Impact 6mm Pro 400 Carbon Arrows - 6 Pack - Our Acu-Carbon process is a continuous fed, single-die, single-mandrel manufacturing methed. This Creates uniform arrows with more consistent spine and weight from dozen to dozen, lot to lot. Every Vital Impact arrow comes off the USA Production line with the same tight specifications year in and year out without the sorting requi9red in overseas production. .006 straightness